They were originally created in the Darklands, as weapons of war (because they can cast fireball but can't run away, and you can stack them into neat pyramids when they are not in use). As in all cases when people try to enslave powerful wizarding-types, the spherical wizards eventually killed many of their masters and escaped.

You see them in all sorts of positions. Some are still slaves that travel from battleground to battleground packed inside a crate filled with straw. Some are masters of men, using charm and domination to enslave servants who push them around and carry their spellbook for them. A few, a precious few, of them are adventurers.

They all enjoy downhill races, during which they can get quite competitive. Some also frequent labyrinths, where they navigate through holes sized exactly for their body.

As a whole, they tend to be pretty idiosyncratic, with lots of visible personality quirks. Very few of them have forgettable personalities. They also change personalities along with their size--small spherical wizards tend to be meek and humble, while large spherical wizards are booming and triumphant.

from a British TV show called The Prisoner

Spherical wizards are a sub-type of wizard. All of this stuff is just a template that you apply on top, when creating a normal wizard. Well, "normal" wizard.

You're a Sphere
The implications of this are obvious. You have no arms, legs, neck. You can't wear armor or clothing unless it is specifically made for you. You are perfectly spherical, and your bone structure is created by the fusion of skull and rib cage. You do not poop; your eldritch biology teleports your waste products to the Cesspool Dimension.

However the most salient feature of this ability is that you cannot move under your own power (unless you use telekinesis or fly or something). If you fall in water, you float face-up. However, on floors that are perfectly flat (mirrors, metal. . . something better than standard dungeon bricks), you can roll yourself at a snail's pace by violently rolling your eyes.

Free Henchman
If you begin play as a spherical wizard, you start with a level 0 henchman, using all the normal henchman rules. Your henchman can either be an Igor (pleasantly unscrupulous but lazy) or a Sisyphus (tireless but painfully moralistic).

Mystic Bounciness
Immune to fall damage, and will bounce back the way they came with 75% of the original inertia. This bounciness doesn't extend to things that aren't hard surfaces, such as the floor of a pit covered with 1' of acid, or anything covered with spikes.

Trample Attack
If another creature pushes you, you can trample over smaller creatures, up to a distance equal to half the pusher's movement speed on your first turn, and a distance equal to the pusher's full movement speed on subsequent rounds (as you accelerate). Your trample attack does 1d6 damage to all creatures your size or smaller within your path. A successful Dex check negates (most monsters have Dex 10). Prone creatures automatically fail their check.

Spherical wizards can cast touch spells through their trample attacks, potentially hitting multiple targets. This is in addition to the normal effects of your trample attack.

Spellbulk
Maximum HP increases by 1 for each spell level they have memorized. And yes, memorizing spells heals them as it increases their maximum HP. If they gain more than 20 HP in this way, they are too large to fit through doors, and their trample damage increases to 2d6. If they gain more than 40 HP in this way, they are too large to fit through hallways, and their trample damage increases to 3d6. This change is magical, and your clothing and gear changes size along with you.

Compress
A spherical wizard can compress things. You can do this as a standard action. Paper is wadded up, wine glasses are shattered, a sliced orange is restored to (near) wholeness, and snowballs are made instantly. This ability does 1d6 damage to non-spherical creatures (save negates). Creatures that are killed by this spell are compressed into monsterballs (they turn spherical, like you, and then petrify, like a giant marble). You cannot compress dead creatures. This is a magical ability with a 50' range.

Monsterballs
Monsterballs can be rolled, just as you can be rolled. They deal damage as you do, based on the size of the original monster (1d6 at medium size, 2d6 at large size, and 3d6 at huge size). If you collide with a monsterball, you can send it in any direction you want except back the way you came from (think pool ball physics). Monsterballs can be attacked and damaged; they have the same AC and HP as the original creature. Whenever they deal damage, they take damage equal to half the damage dealt. They shatter after a fall of any length (they are psuedo-glass). They can be repaired by anything that can repair glass.

If the original monster had an special ability, that ability is transferred to the monsterball. A ghoulball does paralysis on a hit. A dragon ball ignites, and deals its full breath attack damage.

Spherical Wizard SpellsCareen
Level 1 Spherical Wizard Spell
For a number of rounds equal to your caster level, you can charge around under your own power, dealing trample attacks at your leisure. You cannot cast spells during this time, nor use your compress ability.

Absorb Monsterball
Level 1 Spherical Wizard Spell
You touch a monsterball and absorb it into you. You heal 1d4 HP for every HD the original monster had. You also gain any special monsterball ability that the monsterball had as a prepared spell. You can cast this as a touch spell or through your trample attack (as normal for a spherical wizard). You can only cast this converted spell once (as normal for a spell). The spell is lost when you sleep (as normal for a spell).

Seek the Moon
Level 2 Spherical Wizard Spell
You teleport to the moon (which you suspect is either another spherical wizard or the progenitor of your race). This spell doesn't allow you breathe on the moon, nor return from the moon.

Katamari
Level 3 Spherical Wizard Spell
As careen, except that every creature you kill with your trample ability sticks to you, making you a larger ball. Each item that you roll over is also picked up, and added to your bulk. You cannot pick up things larger than you. Each time you increase your mass in this way, increase your trample damage by +1d6.

For example, you are medium sized and roll over 3 orcs: your trample damage increases to 2d6. You could even space this out, so that 1 orc added = +1 damage, 2 orcs = +2, and 3 orcs = the full +1d6. Increasing from large to huge size will require either 12 orcs beyond that, or 3 ogres.